An electronic blood pressure meter measures the systolic and diastolic blood pressure values of a person by wrapping a cuff around his upper arm, pressurizing or inflating this cuff to obstruct the flow of blood in his artery and obtaining blood vessel information (such as Korotkoff sound, pulse wave, eletrocardiograph, etc.). The cuff is required to be pressurized above the systolic blood pressure level and an accurate measurement is not possible if the cuff pressure is insufficient. On the other hand, excessive pressurization of the cuff not only increases the time period required for blood pressure measurement but also causes discomfort to the person whose blood pressure is to be measured.
In view of these facts, there has been proposed an electronic blood pressure meter which provisionally pressurizes the cuff to a certain pressure level and performs a repressurization when any insufficiency of the cuff pressure is detected. More specifically, when any insufficiency of the cuff pressure is detected, a certain value is added to the previous target value and the cuff is repressurized to this renewed target value.
According to this previously proposed electronic blood pressure meter, since the target value for repressurization is predetermined, the cuff pressure may continue to be insufficient even after a repressurization is performed. Therefore, depending on the circumstances, this repressurization or adjustment of an initial pressurization level may be performed a number of times before the cuff pressure reaches a sufficient level, and pressurization of the cuff for such an extended time period may cause not only discomfort to the person but also may generate measurement errors due to the hemostasis which the cuff causes in his arm. In particular, in an electronic blood pressure meter based on the detection of pulse wave as blood vessel information, since any insufficiency of cuff pressure cannot be accurately detected in an early phase of blood pressure measurement and can only be found after the cuff pressure has been reduced to the level of the diastolic blood pressure, the above mentioned problems are aggravated even further.